John howie pollard



(No Model.)

J. H. POLLARD. sToPPBR PoR BOILBR TUBES.

Patented Nov. 28, 1893.

gw Zd krnrns PATENT OFFICE.

JOHN HOWIE POLLARD, OF NEW YORK, N. Y., ASSIGNOR, OF ONE-HALF TO ANDREWPHILP, OF SAME PLACE.`

AsToPPr-:R oR BolLER-TUBES.

SPECIFICATION forming part of Letters Patent No. 509,678, dated ovember28, 1893.

Application led April 3, 1893. Serial No. 468,897. (No model.)

To LZZ whom t may concern:

Be it known that I, JOHN Howie POLLARD, a subJect of the Queen of GreatBritain, residing in the city of New York, county and State of New York,have invented a new and useful Stopper for Boiler-Tubes; and Ido herebydeclare that the `following is a full, clear, and exact description ofmy invention, reference being had to the accompanying drawings.

The object of my invention is to stop up leaking or bursted boiler tubesby utilizing the heat of the boiler to set in operation a novel pluggingdevice, without drawing the tires or interrupting the use of the boiler.

To more particularly describe my novel plugging device, I will refer tothe accompanying drawings.

Figure 1, shows avertical longitudinal section of a boiler tube 7c, withthe plugging device lnserted therein ready for operation,one c nd of theplugging device being shown iu similar section, the other end in sideelevation. The boiler tube and stopper are shown broken, the partsomitted being the continuation of the boilertubeand rod a., of thestopper. Fig. 2 shows the saine section of the tube and `plugging deviceas Fig. 1, and also a similar section of the other end of the pluggingdevice, and the Whole plugging device in operation stopping up the tube.Fig. 3 is a detailed Viewr in cross section of a part of the pluggingdevice shown at g, Figs. l and 2. Fig. LLis another detailed view insimilar section of the same part. Fig. 5 is a detailed view in sectionshowing a modification in construction of the like parts f, f, in Figs.1 and 2. Fig. 6 is a vertical longitudinal section showing amodification in the parts of the plugging de- Vice shown in Fig. 1.

Letter ci, represents a forged metal rod corresponding in length to theboiler tube. The similar collars, b, b, forged upon the rod a, supportthe strong spiral springs c, c, which bear outwardly on the loosecircular Washers d, CZ, facing which are the circular washers e, e',bored with screw thread to fit respectively the screw thread turned onthe ends of the forged rod a. The opposing washers, d and e, embrace andsupport an annular metal band f, and toward their centers are made withbev` eled projections upon which rests the metal coil g. The washers, o3and e', at the other end of the rod, a, are similarly designed tosupport a like metal bandf, and like coil g. The washer e', is flangedat i, to prevent the stopper from entering too far within the tube lo.The metal coil g, Figs. 1 and 2, may be formed by ceiling a strip ofbrass oi' other suitable metal of the desired width and length, bindingthe coil temporarily with wire w, Fig. 3, and dipping the coil firstinto inuriatic acid and then into molten fusible metal. After coolingand removing the tying wire, the coil will remain fastened by thequantity of fusible metal taken up in the process of sweating justdescribed. The coil is then ready to be placed between the washers ateach end of the stopper.

The annular metal bands f,f, Fig. 1, are grooved on the inner side in Vshape as at Z, Figs. l and 2,to facilitate an outward expansion of themetal band undei pressure as shown in Fig. 2; another form of groove,shown at Z, Fig. 5, may also be used to advantage. I prefer to make theexpanding band of lead,

`but do not limit myself to the use of metal and any other suitableexpansible material may be used for this purpose. The washers, CZ, d, e,e', and the metal bands,f,f, are made of such size as to allow thestopper to freely enter the tube until arrested by the flange t', on theWasher e. The pairs of Washers and inclosed metal bands are arrangedapart from each other on the rod, in' order to include as much aspossible of the boiler tube. The springs, c, c, are compressed byscrewing the washers e, e on the rod a, against the inetal coil g, bythe nut ends h, h, and locked by the jam nuts g, g.

The operation of my invention is as follows: The stopper constructed asdescribed is inserted within the boiler tube. The heat of the boilertube immediately liquefies the fusible metal fastening of the coil g,which, being loosened, expands as shown in Figs. 2 and 4. The expansionof the coils g, frees the Washers d, CZ, and the springs c, c, whichcompress the bands,f,f, expanding them at Z, Fig. 2, out- Wardly againstthe side of the boiler tube, thus completely closing the tube at bothends. The bands f,f, are preferably made of a width slightly less thanthe space between the opposing faces of the Washers when held in checkby the fusible coil g, to enable the springs, c, c, to gain momentum onbeing released. To remove the stopper, it is only necessary to unscreWthe Washer e', after loosening the lock nut g, and while holding thesquared end of the rod `at a. Instead of the band f, and the fusiblecoil g, shown in Figs. 1 and 2, tvvo U shaped lead pieces f, f', Fig.6,witl1 their opposing faces beveled as at Z, may be used, the

loose washer d, being formed With a 'p'rojecting bearing to fit into acorresponding space, provided in the washer e, or eI. This space beingfilled with fusible metal imafter the spring has been com pressed-,th"eloose Washer is held back against the spring. Within the boiler tube theheat as before liqueties the .fu-L

sibleimetal, which escapes between the rod a, and the loose Washer d,and the lead pieces f,

zo f thereupon compressed and expanded, close up the tube, as beforedescribed. To permit the vescape, of the yfusible metal in the form ofconstruction shown in Fig. 6, and to avail of the steam in theboilertube to aid in expanding the lead band or pieces, the borings quire alarge escape of Asteam in the boiler tube to furnish the necessary.pressure to expand the plugging band.

I claiml. In a boiler tube stopper the combination of an expansible bandwith compressing washers, a fusible check, `and a pressure spring,substantially as described.

2. In a boiler tube stopper the combination of an expansible band withexpanding mechanism, and a fusible check, substantially as described.

3. A boiler tube stopper, consisting of a rod carrying at each end apressure spring, coinpressing Washers, a fusible check, and anexpansible band, constructed and arranged substantially as described. ip y l 4. In a boiler tube stopper thecombination of the pressure spring,the compressingjvashers, the fusible metal coil, and the ex-ppansiblebaud, 'constructed and arranged substantially asdescribed. y p y 5. In aboiler tube stopper the combination of the pressurespring thecompressing washers, the fusible metal, and theA expansible band,constructed and arranged substantially as described. D n p y JOHN HOWIEPOLLARD. Witnesses:

EUGENE TREADWELL, Jos E. PIDGEON.

